Helmets, shoulder pads, thigh pads and other protective gear is used by people in various situations to help protect the body from injury due to impacts. In contact sports such as football, hockey and lacrosse, impacts to the head can be especially problematic.
Protective gear typically aims to absorb impact energy through the use of compressive pads. Such pads do absorb some energy, but are not sufficient. One problem is that when pads reach their compression limit they lose effectiveness. Another problem is that only the portion of the pad directly under the impact location, and areas close to the impact location, is compressed, which limits the pad volume involved in energy absorption and thus limits its effectiveness.